Compound of 稲(ina, “rice plant”, ancient bound-form reading of modern ine) +‎ 妻(tsuma, “wife, spouse”) or 夫(tsuma, “husband, spouse”).[1][2][3] The tsuma changes to zuma as an instance of rendaku (連濁).

A belief in ancient times was that rice plants would mate with or otherwise be fertilized by lightning,[1][2][3] a frequent occurrence in the late summer and autumn when rice plants come to fruition.[3]